US5472812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a photomask pattern
Assignee: Canon Inc
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Filing: 1994-06-27
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Granted: 1995-12-05
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Expires: 2014-06-27
Abstract
Abstract A silicon film is formed on the surface of a substrate for a photomask, and a silicon nitride film is formed thereon. Then the silicon film and the silicon nitride film are patterned into desired shapes by photolithography method, the edge portion of the patterned silicon film is oxidized to provide a translucent region consisting of a silicon oxide film only on the edge portion, and the silicon nitride film is removed.
Inventors
- 👤 Yasuhiro Sekine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:36
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/29; G03F1/32; H; H10; H10P; H10P76/00; H10P76/40; H10P76/408; H10P76/4085
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
91 words
A method for forming a phase shift photomask, comprising the steps of: forming a light shielding layer with a silicon film on the surface of a substrate for the photomask and an antioxidizing layer with a silicon nitride film on the silicon film; patterning the silicon film and the silicon nitride film into a desired shape, leaving an edge portion of the patterned silicon film exposed; forming a translucent portion on the edge portion by oxidizing the edge portion of the patterned silicon film; and removing the patterned silicon nitride film.
Claim 2
Independent Claim
91 words
A method for forming a phase shift photomask, comprising the steps of: forming a light shielding layer with a silicon film on the surface of a substrate for the photomask and an antioxidizing layer with a silicon nitride film on the silicon film; patterning the silicon film and the silicon nitride film into a desired shape, leaving an edge portion of the patterned silicon film exposed; forming a translucent portion on the edge portion by oxidizing the edge portion of the patterned silicon film; and removing the patterned silicon nitride film.
Claim 3
Dependent Claim
104 words
A fabrication method for a semiconductor device, comprising the steps of: forming a phase shift photomask by forming a light shielding layer with a silicon film on the surface of a substrate for the photomask and an anti-oxidizing layer with a silicon nitride film on the silicon film; patterning the silicon film and the silicon nitride film into a desired shape, leaving an edge portion of the patterned silicon film exposed; forming a translucent portion on the edge portion by oxidizing the edge portion of the patterned silicon film; removing the patterned silicon nitride film; and forming a desired circuit pattern on the photomask.
Claim 4
Dependent Claim
104 words
A fabrication method for a semiconductor device, comprising the steps of: forming a phase shift photomask by forming a light shielding layer with a silicon film on the surface of a substrate for the photomask and an anti-oxidizing layer with a silicon nitride film on the silicon film; patterning the silicon film and the silicon nitride film into a desired shape, leaving an edge portion of the patterned silicon film exposed; forming a translucent portion on the edge portion by oxidizing the edge portion of the patterned silicon film; removing the patterned silicon nitride film; and forming a desired circuit pattern on the photomask.
Claim 5
Dependent Claim
23 words
The fabrication method according to claim 2, further including a process of exposing a photo resist on the semiconductor substrate using the mask.
Claim 6
Dependent Claim
42 words
A phase shift photomask, comprising: a translucent support; a light shielding pattern of a silicon film on said support; and a translucent phase shifter of silicon nitride formed by selective oxidation and provided at the edge portion of said light shielding pattern.
Claim 7
Dependent Claim
42 words
A phase shift photomask, comprising: a translucent support; a light shielding pattern of a silicon film on said support; and a translucent phase shifter of silicon nitride formed by selective oxidation and provided at the edge portion of said light shielding pattern.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-04 | 1999-06-05 | 1999-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-04 | 2003-06-05 | 2003-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-04 | 2007-06-05 | 2007-12-05 | $7700.00 | Window Closed / Lapsed |